Aim of the study Out-of-hospital cardiac arrest (OHCA) is a major cause of death in the western world. We wanted to study changes in survival over time and factors linked to this in a region which have already reported high survival rates. Methods We used a prospectively collected Utstein template database to identify all resuscitation attempts in adult patients with OHCA of presumed cardiac origin. We included 846 resuscitation attempts and compared survival to discharge with good outcome in two time periods (2001–2005 vs. 2006–2008). Results We found no significant differences between the two time periods for mean age (71 and 70 years ( p = 0.309)), sex distribution (males 70% and 71% ( p = 0.708)), location of the OHCA (home 64% and 63% ( p = 0.732)), proportion of shockable rhythms (44% and 47% ( p = 0.261)) and rate of return of spontaneous circulation (38% and 43% ( p = 0.136)), respectively. Bystander cardiopulmonary resuscitation (CPR), however, increased significantly from 60% to 73% ( p < 0.0001), as did the overall rate of survival to discharge from 18% to 25% ( p = 0.018). In patients with a shockable first rhythm, rate of survival to discharge increased significantly from 37% to 48% ( p = 0.036). In witnessed arrest with shockable rhythm survival to discharge increased from 37% to 52% ( p = 0.0105). Conclusion Overall, good outcome is now achievable in every fourth resuscitation attempt and in every second resuscitation attempt when patients have a shockable rhythm. The reason for the better outcomes is most likely multi-factorial and linked to improvements in the local chain of survival.